OAKLAND, CA - JUNE 30: Rihanna performs part of her Loud Tour at Oracle Arena on June 30, 2011 in Oakland, California. (Photo by Tim Mosenfelder/Getty Images)

PHOTO: Getty Images

She was one of the pioneers of the pop star pantsless movement--and with a bum like that, who could blame her!?--and now, Rihanna will officially put her derriere on the line for a campaign. According to Vogue UK, "The singer will appear in campaigns for Emporio Armani Underwear and Armani Jeans from autumn/winter 2011-12. Although no images have yet been released, Armani has revealed that the shoot took place recently in New York and will launch in September."